LIFE HISTORY OF A FERN 
149 
FIG. 107. Portion of the rhizome of the common brake (Pteris aquilina) 
showing a cross-section view at the right. The two dark areas are scler- 
enchyma. 
FIG. 108. Cross-section of the rhizome of the bracken fern (Pteris aqui- 
lina), showing the tissue systems. Greatly magnified. 
